Self-winding photographic shutter with an electronic timing device



Aug. 5, 1969 w. STARP ET AL 3,459,112

SELF-WINDING PHOTOGRAPHIC SHUTTER WITH AN ELECTRONIC TIMING DEVICE FiledDec. 25, 1966 2 Sheets-Sheet 1 IN VEN TORS Franz W R. Starp, ReinholdBot! miw ATTORNEY Aug. 5, 1969 w, STARP ET AL 3,459,112

SELF-WINDING PHOTOGRAPHIC SHUTTER WITH AN ELECTRONIC TIMING DEVICE FiledDec. 23. 1966 2 Sheets-Sheet 2 fi -i INVEWTORS ATTORNEY I United StatesPatent Office 1m. 01. obsb 9/26 US. Cl. 95-60 9 Claims ABSTRACT OF THEDISCLOSURE A self-winding photographic shutter having a shutter bladesystem which is infiuenceable during the exposure run-off by anelectronic timing device having an electromagnet and an armature. Thearmature is caused to make contact with the electromagnet and the timingdevice is switched on as a function of the actuation of a winding andrelease lever. The photographic shutter has an overpull pawl serving totransfer the shutter blade system into a wound position. The over-pullpawl is linked and biased into engagement with the winding and releaselever. A driver is provided which is movable with the shutter bladesystem and causes the armature, mounted on an armature lever, to contactthe electromagnet during the winding process. This action also transfersa formed portion of the armature lever, acting as an open time lock,into a locked position. After the wound position has been reached, thedriver is held in a fixed position against the armature lever so thatthe over-pull pawl is enabled to move relative to the winding andrelease lever against the effect of the over-pull spring, until theshutter blade system is released.

The invention relates to a self-winding photographic shutter with ashutter blade system which is influenceable during the exposure run-offby an electronic timing device having an electromagnet and an armatureassociated therewith, whereby the armature is caused to make contactwith the electromagnet and the timing device is switched on as afunction of the actuation of a winding and release lever.

It is an object of this invention to provide a shutter of the above typethat is particularly simple in construction requiring a minimum of partswhile assuring reliable runoff operation. It has now been found that theforegoing and other objects and advantages can be readily attained in aphotographic shutter having an over-pull pawl serving to transfer theshutter blade system into a wound position wherein the over-pull pawl islinked and biased into engagement with the winding and release lever. Inaddition, a driver is provided that is movable with the shutter bladesystem and causes the armature, mounted on an armature lever, to contactthe electromagnet during the winding process. This action also transfersa formed portion of the armature lever, acting as open time lock, into alocked position.

After the wound position has been reached, the driver is held in a fixedposition against the armature lever so that the over-pull pawl isenabled to move relative to the winding and release lever, against theeffect of the overpull spring, until the shutter blade system isreleased. This simple construction provides for causing the armature tocontact the electromagnet so that the part acting as open time lock canrelease'the shutter blade system for run-oil at the proper moment duringthe winding and release process. Special actuating members are notneces-3,459,112 Patented Aug. 5, 1969 sary due to the fact that the armatureand the lock part are moved by the shutter blade system.

One design of a highly desirable shutter blade system for providing arelatively simple self-winding shutter requiring a minimum of parts in aparticularly advantageous manner can be attained according to thisinvention by having a shutter blade system consisting of twoconcentrically mounted blades that runoff successively. In this system,the opening blade which runs off first, has a winding arm disposed inthe range of motion of the over-pull pawl, and a driver which cooperateswith the armature lever during the winding process. The second shutterblade, for ending the exposure, is provided with a projection which,when the shutter blade system is transferred into the wound position, isengaged by the formed portion or projection of the armature lever actingas open time lock. In a further advantageous embodiment of theinvention, the arrangement of this formed portion or projection inrelation to the rotational axis of the armature lever is such that theshutter blade is able to move the armature lever to the side when theelectromagnet is currentless, thus eliminating the use for a specialreturn spring for the armature lever.

To further perfect the invention toward the end of achieving reliableoperation of the electronic timing device which cooperates with theshutter blade system, the invention further provides a short-circuitswitch for the electronic timing device that enables a capacitor of thisdevice to charge. The short-circuit switch is so disposed in the rangeof motion of the over-pull pawl that this switch is opened after releaseof the shutter blade system by the over-pull pawl under the effect ofthe over-pull spring following the motion of the winding and releaselever.

In another embodiment of this invention additional structuralsimplification of the shutter arrangement may be achieved by providing aleaf spring instead of the overpull pawl and over-pull spring.

Various other objects, features and advantages of this invention will beapparent from the following specification, claims and the drawingappended hereto wherein: 7

FIGURE 1 is a top view of the self-winding shutter of this invention inits normal position with an electronic timing device illustratedschematically.

FIGURE 2 is a view illustrating the shutter of FIG- URE 1 without theschematically illustrated electronic timing device showing the parts inthe position assumed after transfer of the shutter blade system into thewound position.

' FIGURE 3 is a view similar to FIGURE 2 illustrating the shutter inopen position, wherein the over-pull pawl, released with the release ofthe shutter, has opened the charge starting contact of the electronictiming device.

Referring now in detail to the drawings, a plate, designated byreference numeral 1, carries the essential shutter parts of aphotographic shutter designed to be self-Winding. A shutter bladesystem, illustrated in its normal position in FIGURE 1, is disposed onthe plate 1, serves to cover an exposure aperture 1a machined intoplate 1. The shutter blade system is formed of two shutter blades 2 and3 which run off successively so that blade 2 opens the aperture 1a afterrelease and the second shutter blade 3 follows the other blade after theelapse of a certain exposure time to again close the exposure aperturela. Cooperating with each of the shutter blades 2 and 3 are drivesprings4 and 5 "biased against pins 7 and 8, respectively on the blades 2 and3. The blades are designed as segment-like blades and are mounted on thesame axis on a pin 10 fastened to the plate 1. In the normal positionillustrated in FIGURE 1, the opening blades v2 is biased by the drivespring 4 against a fixed pin 12 while the pin 8 of the closing blade 3is biased against the edge of the opening blade 2 by the drive spring 5.

In order to cock the two springs 4 and 5, a spring loaded winding andrelease member 15, designed in the disclosed embodiment as a two-armedlever, is pivotally mounted on the plate 1 by means of a pin 14. One arm1'5a provides a means for actuating the winding and release lever 15,and the other arm 15b is linked to an over-pull pawl 17 in the form of aone-armed lever which is biased into contact with a pin 19 of thewinding and release lever 15 under the force of an over-pull spring 18.The overpull pawl 17 cooperates with the opening blade 2 which isprovided with a winding arm 2a for engagement with a tab 17a of theover-pull pawl 17 in order to transfer the shutter blade system into thewound position during the winding and release motion.

As may be seen further from the drawings, the shutter blade system 2, 3cooperates with an armature lever 21 for the achievement of varyingexposure times. The lever 21 is pivotally mounted on the plate 1 andcarries an armature 22 which cooperates with an electromagnet 23controlled by an electronic trip circuit. In detail, the arrangement issuch that the armature 22 is caused to make contact with theelectromagnet 23 by the shutter blade system 2, 3 during the windingmotion. For this purpose, a projection 2b is provided on the openingblade 2 for cooperation with a striking tab 21a disposed on the armaturelever 21 in order to position the armature lever. An additional stop 21balso disposed on the armature lever 21, serves as open time lock andpositions itself in front of a knob 3a of the closing blade 3 when thearmature 22 makes contact with the electromagnet 23 thereby holding theclosing blade 3 in the open position as long as current flows throughthe electromagnet.

The trip circuit serving to control the electromagnet 23 consistsessentially of two emitter-coupled transistors T and T a capacitor C, aphoto resistor 26 and a battery 27 for supplying current. In place ofthe photo resistor 26, an infinitely variable resistor or severalgradated fixed resistors and a setter serving for setting a certainresistance value may also be provided. The connection of the electronictrip circuit with the battery 27 is established by a switch S having acontact tongue 28 which is transferred into a contact making position bya projection 150 on the winding and release lever 15 at the end of thewinding process, expediently after the armature 22 has made contact withthe electromagnet 23. An additional switch S forms part of the tripcircuit and bridges the capacitor C in the normal position of theshutter and is opened advantageously by the over-pull pawl 17 underincreased spring pressure after the release of the shutter blade system.In detail, the arrangement is such that the overpull pawl 17 is providedwith a projection 17b which strikes against the contact tongue 30 of theswitch S and opens it under the eflect of the cocked over-pull spring 18after release of the shutter blade system 2, 3.

The operation of the above described shutter arrangement illustrated inthe drawings is as follows:

When the winding and release lever 15 is actuated, the over-pull pawl 17first moves clockwise in the manner of a lever rigidly joined to thewinding lever through which motion the two shutter blades 2 and 3 areturned counterclockwise about the bearing pin due to the fact that thetab 17a engages the winding arm 2a, thereby putting the drive springs 4and 5 under increased tension and keeping the shutter aperture 1aclosed. At the end of the winding process, the projection 2b of theopening blade 2 strikes against the tab 21a of the armature lever 21,and pivots it in a counterclockwise direction until the armature 22makes contact with the electromagnet 23. In this phase of the operation,as shown in FIGURE 2, the locking stop 21b disposed on the armaturelever 21 has simultaneously positioned itself in front of the knob 3a ofthe closing blade 3'. In further moving the winding and release lever15, it travels an excess distance, whereby the over-pull pawl 17 turnsrelative to the lever 15, in-

creasing the tension of the spring 18, due to the fact that the openingblade 2 is disposed firmly against the armature lever 21. The excessdistance that the lever 15 moves is utilized to provide positiveengagement of armature 22 with the electromagnet 23 and also to closethe switch S, by means of the projection on the winding and releaselever 15 as illustrated in FIGURE 2. Consequently, the electronic tripcircuit is connected by the battery 27 so that the electromagnet 23receives current via the transistor T while transistor T remainsblocked. Finally, at the end of the winding and release motion, theover-pull pawl 17 disengages from the winding arm 2a of the openingblade 2 which returns under the influence of its drive spring 4 into thestarting position fixed by pin 12, thereby opening the exposure aperture1a, while the closing blade 3 is held in the open position by thelocking stop 21b. With the release of the opening blade 2 by theover-pull pawl 17, the pawl 17 follows the motion of the winding andrelease lever 15 under the effect of the cooked over-pull spring 18until it strikes pin 19, whereby the projection 17b strikes against thecontact tongue 30 of switch S opening it as shown in FIGURE 3, whichresults in the charging of the capacitor C.

When the capacitor C has reached the base potential of transistor T in atime span depending on the resistance value of the photo resistor or ofa :manually variable resistor, it conducts while transistor T issuddenly blocked. This immediately causes the electromagnet 23 to becomecurrentless so that the closing blade 3 under the effect of its spring5, is enabled to turn the armature lever 21 clockwise thereby pushingthe locking stop 21b to the side and returning to the closed position.This return motion of the closing blade 3 can take place practicallysimultaneous with the collapse of the magnetic field in theelectromagnet 23 because no self-retardation occurs due to the specialconfiguration of the armature lever 21, the locking stop 21b and theknob 3a of the closing blade 3 whereby the locking stop 21b may bepositioned advantageously between the pivot point of the armature lever21 and the knob 3a of the closing blade 3 and also due to the relativelysmall mass to be moved.

It will be understood that the foregoing description with the details ofexemplary structure is not to be construed in any way to limit theinvention, but that modifications may be made thereto without departingfrom the scope of the invention as set forth in the following claims.

Having thus described our invention, we claim:

1. A self-winding photographic shutter comprising: a shutter bladesystem; a winding and release lever; an electronic timing device havingan electromagnet and a cooperating armature influencing said shutterblade system during the exposure run-off, wherein said armature contactsthe electromagnet and said timing device is switched on upon actuationof said winding and release lever, an over-pull pawl linked with saidwinding and release lever and biased into engagement therewith duringthe cocking movement by an over-pull spring, said pawl engaging saidshutter blade system and transferring the latter into a wound positionwhen the cocking and release lever is actuated, whereby biasing meansfor said shutter blade system is cocked; an armature lever movablymounting said armature, said armature lever having a projection thereon;and a driver movable with said shutter blade system, said driver beingoperably connectable with said armature lever to cause the said armatureto make contact with said electromagnet during the winding process andto transfer said projection on said armature lever into a position inwhich the projection prevents the shutter blade system from closing theshutter opening, and wherein, after attainment of the wound position,said driver is held in a fixed position against said armature leverenabling said over-pull pawl to move relative to the winding and releaselever against the effect of said fver-pull spring until said shutterblade system is re eased.

2. The photographic shutter of claim 1 wherein said shutter blade systemhas an opening blade and a closing blade concentrically mounted forsuccessive running off; said opening blade adapted to run off first,having a winding arm disposed in the range of motion of said over-pullpawl and wherein said opening blade supports said driver for engagementwith said armature lever during the winding process; said second closingblade, adapted to end the exposure, having a projection for engagingsaid projection of said armature lever which positions itself adjacentthereto during the transfer of the shutter blade system into the woundposition.

3. The photographic shutter of claim 2 wherein said armature lever isconfigured so that said projection is a formed portion positioned inrelation to the rotational axis of said armature lever in such a mannerthat said closing blade is enabled to push said armature lever to theside when said electromagnet is currentless.

4. The photographic shutter of claim 1 wherein said electronic timingdevice has a short-circuit switch and a capacitor 'which is chargeableupon actuation of said short-circuit switch, said short-circuit switchbeing disposed in the range of motion of said over-pull pawl so that itis opened by said over-pull pawl following the motion of said windingand release lever under the effect of said over-pull spring after therelease of said shutter blade system.

5. The photographic shutter of claim 1 wherein said over-pull pawl andsaid over-pull spring are in the form of a leaf spring.

6. A self-winding photographic shutter comprising: shutter blade means;winding and release means operably connected to said shutter blademeans; electronic timing nected to said shutter blade means ;electronictiming means having a cooperating armature and electromagnet controllingsaid shutter blade means during exposure runoff, said winding andrelease means being operable to cause said armature to contact saidelectromagnet and to cause said timing device to be switched on; anover-pull pawl pivotally mounted on said winding and release means andbiased into engagement therewith by over-pull biasing means, said pawlbeing operably connected to said shutter blade means for transferringsaid shutter blade means into a wound position; a pivotally mountedarmature lever supporting said armature, said lever having engagingmeans thereon; and a driver 9n said shutter blade means supported formovement therewith, said driver being connectable with said armaturelever to cause said armature to make contact with said electromagnetduring the Winding process and to transfer said engaging means on saidarmature lever, which engaging means act as an open time lock, into alocking position, and wherein after attainment of the wound position,said drive is held in a fixed position by said armature lever enablingsaid overpull pawl to move relative to the winding and release meansagainst the effect of said over-pull biasing means until said shutterblade means is released.

7. The photographic shutter of claim 6 wherein said shutter blade meanshas an opening blade and a closing blade coaxially mounted forsuccessive run-off; said opening blade being adapted to run-off firstand having a winding arm disposed in the range of motion of saidover-pull pawl, said opening blade supporting said driver so that saiddriver is engageable with said armature lever during the windingprocess; and wherein said closing blade, adapted to end the exposure, isconnectable with said engaging means on said armature lever whichpositions itself adjacent thereto during the transfer of the shutterblade means into the wound position.

8. The photographic shutter of claim 7 wherein said armature lever isconfigured so that said engaging means is a formed portion positionedrelative the rotational axis of said armature lever so that said closingblade is enabled to move said armature lever out of the way when saidelectromagnet is currentless.

9. The photographic shutter of claim 6 wherein said electronic timingmeans has a short circuit switch and a capacitor which is chargeableupon actuation of said shortcircuit switch, said short-circuit switchbeing disposed in the range of motion of said over-pull pawl so that itis opened by said over-pull pawl under the effect of an overpull springfollowing the motion of said winding and release means after the releaseof said shutter blade means.

References Cited UNITED STATES PATENTS 3,191,511 6/1965 Burgarella eta1. -60 3,208,365 9/1965 Cooper et al 95-60 NORTON ANSHER, PrimaryExaminer DAVID B, WEBSTER, Assistant Examiner

